Unknown part fallen off

[dsio]

Ive just found a part sitting under the drivers seat in my '85 318i.

Its a piece of pipe, about two inches along, and bent to one side a bit, its black rubber, about 2 and a half inches in diameter.

On one end of the pipe, there are three rubber tabs comming off the edges of the opening. Each about 1/2 an inch long.

There is a sensor by the looks in the side of the pipe. On the outside of the pipe there is a plug with two pins in it, and a figure eight shape surround to the two pins cut into the round plug. It goes through to the inside of the pipe, where there is a small intrusion into the pipe, about 1/4 inches long, that looks like a pencil rubber, and appears to have a small hole in the end of it.

It has the BMW seal printed into the rubber, and the number 1 284 288 V7

It looks important, and I dont think its meant to be under the driver's seat. anyone know what this could be?

[Jos]

RealOEM search says Airbox lol..

http://www.realoem.com/bmw/showparts.do ... g=20&hl=15

Stick a pic up of it, might help a little bit

[dsio]

Mate thats it, thats exactly it. What the hell is it doing under my seat? lol.

What does this part actually do, and how is the car effected by not having it installed.

[Jos]

lol...

erm does your engine have an induction kit on it perhaps? Or a cone filter?

Have a look in your engine bay, the airbox should be on the front passenger side of the car.

What does it do.. it stops crap from getting into the engine, very important as gravel and rock don't get on well with high speed metal parts..

[dsio]

I have an airbox, its the large plastic box with rust grime all over it. Its there, and there is no cone filter, thats for sure.

Is it possible for the car to run without this particular part, and could it have anything to do with the fact that this card is loud as hell?

Can you think of any reason why it would be removed? Its not damaged in any way by the looks.

[Ziggy]

Might be getting the wrong end of the stick here, but it looks to me like it's just the pipe that attaches to the intake on the airbox, not the whole thing?!!?

Not had a 318i, but there was a very similar thing on my 320 - just went from the intake to a a cutout behind the lights as a cold air feed. Sounded a bit nicer with it removed, but it probably does a good job!

[dsio]

Yea, its not the whole thing. The car is very loud when it runs, partly because there is no noise dampening stuff under the bonnet, and partly because its just plain noisy. Will this part make things quieter, or noisier?

And why would someone take it off other than to change the noise? Does it net some sort of performance improvement? And should I put the thing back? I was under the impression it was important due to the fact that it had a sensor thingy on it. Is there any harm in not using it, like previously suggested, can it cause damage to the engine?

[Ziggy]

Yea, its not the whole thing. The car is very loud when it runs, partly because there is no noise dampening stuff under the bonnet, and partly because its just plain noisy. Will this part make things quieter, or noisier?

And why would someone take it off other than to change the noise? Does it net some sort of performance improvement? And should I put the thing back? I was under the impression it was important due to the fact that it had a sensor thingy on it. Is there any harm in not using it, like previously suggested, can it cause damage to the engine?

There was no sensor on mine, so I'll have to pass on that one...

Just the pipe though, will reduce induction noise & probably improve performance (though I wouldn't expect it to be by a noticable amount).

[dsio]

Noise reduction is always a plus. How do I go about installing the thing, and how difficult is the procedure?

Also, do I need to take the airbox off / apart, and if so, should it be cleaned out after 20 years?

Thanks for the help by the way!

[dsio]

OK, this is pretty messed up. I have taken the bottom of the air box off (the part with the filter in it) to install this suction tube thing, and noticed something was wrong.

There is a massive, jagged edged hole in the bottom of this box, about 1.5 times the size of the hole that this suction pipe connects to. So its sucking air in from the normal hole, at the front, with no suction pipe on it diverting it from behind the headlight, and its ALSO sucking air from underneath the airbox through this big hole.

Given I have two massive gaping holes in the bottom of my airbox at the moment, if I replace this metal filter cover piece, and use the suction pipe, will my BMW sound like a regular 1.8 litre M10 rather than a small truck.

I guess the previous owner couldnt afford a K & N cone filter, and decided to make his own.

If I replace all this stuff, to make it original again, will I notice a decrease in power along with a decrease in noise, or is the air box sucking air from the from sufficient on its own?

[Guest]

someones just drilled the airbox to make more noise! - proabably taken the front part off for more effect too, wont make much difference to the filtering of the air, but i guess itll make the iar filter itself getting dirtier quicker

[Jos]

OK, this is pretty messed up. I have taken the bottom of the air box off (the part with the filter in it) to install this suction tube thing, and noticed something was wrong.

If I replace all this stuff, to make it original again, will I notice a decrease in power along with a decrease in noise, or is the air box sucking air from the from sufficient on its own?

Should be an increase in power as the air in the engine bay is warmer normally (less dense) than the air being fed from the front of the car.

I dunno if this is whats causing the noise, normally you can only hear induction noise at highish revs, and not from inside the car. Noticable outside though.